The present invention relates to a method for guarding a cargo on a trailer without a peripheral sidewall against rock damage and a rock guard for a trailer constructed in accordance with the teachings of the method.
As a trailer is pulled along a road by a tow vehicle, rocks invariably are thrown up from the road surface. The rocks may originate from passing vehicles, or may originate from the tow vehicle. Some trailers have a peripheral sidewall that protects the cargo on the trailer from rock damage. With trailers that do not have a peripheral sidewall, the cargo is exposed and can sustain rock damage. For that reason, rock guards have been developed that mount onto trailers in order to protect cargo from rock damage. These rock guards are commonly positioned on trailers used to haul boats, motor vehicles, and snow mobiles; to name just a few of many applications.
The present invention relates to a method for guarding a cargo on a trailer without a peripheral sidewall against rock damage and a rock guard for a trailer constructed in accordance with the teachings of the method.
According to one aspect of the present invention there is provided a method of guarding a cargo on a trailer without a peripheral sidewall against rock damage. The method involves tensioning a sheet of flexible non-supporting material to form a protective shield.
According to another aspect of the present invention there is provided a rock guard for a trailer which is constructed in accordance with the teachings of the method. The rock guard includes at least one tensioning cable and at least one sheet of flexible non-supporting material having sufficient tensile strength to withstand tensioning. The sheet of material has means for accommodating the tensioning cable. At least one support member is provided having a first end and a second end. The first end is adapted to receive the tensioning cable. The second end is adapted for attachment to a trailer frame. At least one cable tensioning member is provided, whereby the sheet of material is tensioned with the tensioning cable to form a protective shield.
The invention, as described, involves tensioning a sheet of non-supporting material and positioning the sheet on a trailer to provide protection to the cargo from any rocks or debris rising from the road or the wheels of the towing vehicle.
Although beneficial results may be obtained through the use of the rock guard, as described above, it is desirable that the sheet of material be shaped to match the contours of the trailer. Even more beneficial results may, therefore, be obtained when at least one secondary support member is provided. The secondary supports help the sheet of material maintain a desired shape. Each secondary support has a first end and a second end. The first end is adapted to receive the tensioning cable. The second end is adapted for attachment to a trailer frame. It assists in promoting the desired shaping of the protective shield when the secondary support member is in an angularly offset orientation.
Although beneficial results may be obtained through the use of the invention, as described above, boat trailers have a front mounted winch that is used to pull a boat out of the water and onto the trailer. It is, therefore, preferable that the protective shield be removable in order to allow unfettered access to the front of the trailer when launching or recovering the boat. Even more beneficial results may, therefore, be obtained when the second end of each support member has a detachable trailer frame attachment bracket. This allows the attachment bracket to be attached to the trailer frame, and the support member to be attached to and detached from the attachment bracket, as required. For this purpose it is preferred that the attachment bracket have a male coupling and the support member a female coupling. It has been found that it is most convenient when the secondary support members are positioned in pockets in the sheet of material. The tensioning cable can be extended through an aperture at the first end of the secondary support member to prevent the secondary support member from being withdrawn from the pocket in the sheet of material.
There are various cable tensioning mechanisms that can be used with the rock guard, as descried above. Beneficial results have been obtained through the use of a cable tensioning member that has a pivotally mounting cam member. The tensioning cable can be tensioned by moving the cam member about a pivot.
Although beneficial results may be obtained through the use of the invention, as described above, even more beneficial results can be obtained when the sheet of non-supporting material has a plurality of secondary attachment straps by which an edge of the sheet adjacent the frame of the trailer can be secured to the trailer, whereby the non-supporting material can be tensioned between the straps and the tensioning cable.
Although beneficial results may be obtained through the use of the invention, as described above, even more beneficial results can be obtained when the sheet of non-supporting material is divided into two sheets of non-supporting material, each of the two sheets being a mirror image of the other, one of the two sheets being securable at one side of the trailer and another of the two sheets being securable at another side of the trailer, the two sheets thereby severing to protect a load on the trailer from rock chips. The two sheets allow more ready access to the primary support member without reducing the level of protection afforded by the invention.
Although beneficial results may be obtained through the use of the invention, as described above, even more beneficial results can be obtained when the tensioning cable has a first end and a second end, both of the first end and the second end having attachment loops by which the tensioning cable is detachably securable to each of the support member and one of the cable tensioning members.